[技术]Arizona眼睛模型 [复制链接]

简介 79AOvh  
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 U<|kA(5  
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模型 H1N_  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 H,9e<x#own  
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. IKb 7#Ut  
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光源 /m%i"kki  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 |d?0ZA:z  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 a$.(Zl  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 t5G@M&d4Eo  
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视网膜的散射 (0g@Z`r  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 +FRXTku(  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 R_eKKi@VH  
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脚本 |f;u5r!^=  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ,Ua`BWF  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 6 6WAD$8$  
余下的脚本计算与屈光度有关的所有参数。 IFYGl  
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分析 $e1==@ R  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 c,-3+b  
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脚本代码 ZE863M@.  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. :1NF#-2\f  
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Dim entity As T_ENTITY 2&7:JM~#  
Dim op As T_OPERATION ")LcB'C  
Dim mat As T_MODELMATERIAL Ucr$5^ME  
Dim A As Double Q{1Q w'+@  
Dim pupilDiam As Double Ze_4MwCW  
Dim eID As Long w6(E$:#d  
Dim parID As Long -,+zA.{+W  
Dim count As Integer sw A^oU  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double #m[R1G#  
Dim tlens As Double, nlens As Double 5jAiqJq~y:  
Dim curv As Double, conic As Double mDZ/Kp{  
Dim ok As Long 5'>DvCp%M  
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Sub Main b8Gu<Q1k  
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    '用户输入对话框 k'Is]=3  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 NbnahhS  
        TextBox 220,21,40,21,.TextBox1 'default: 0 hq
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        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 SbS*z:  
        OKButton 40,91,90,21 ehehTP  
        CancelButton 190,91,90,21 EY'kIVk  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 W !TnS/O_1  
        TextBox 220,49,40,21,.TextBox2 'default: 4 p,#t[K  
    End Dialog jNRR=0  
    Dim dlg As UserDialog KWwEK]  
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    ok = Dialog (dlg) UqHk
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    If ok=0 Then    'cancel button was pressed S~L;oX?(!  
        Print "Execution cancelled." o3C7
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        End o%Ubn*  
    End If G':wJ7[]`  
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    'Assign accommodation and pupil diameter & use defaults if field left empty Ed">$S  
    If dlg.TextBox1 = "" Then 'YKyY:eZ  
        A = 0           'Default accommodation V ,# |\  
    Else E
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        A = CDbl(dlg.TextBox1) Ss>ez8q  
    End If _"nzo4e0  
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    If dlg.TextBox2 = "" Then C1/qiSHsh  
        pupilDiam = 4   'Default pupil diameter PD,s,A  
    Else 'F-;uN  
        pupilDiam = CDbl(dlg.TextBox2) XR2Gw4]  
    End If ldFK3+V  
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    Print " " jTSN`R9@  
    Print "Accommodation = " & A & " Diopters" mV~aZM0'  
    Print "Pupil Diameter = " & pupilDiam & " mm" 0<ze'FbV]  
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    ' Calculate new parameters with accommodation R*S9[fqC[  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness 3:H[S_q  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens !]#@:Z  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens ,Q%q!#@  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens _mBFmXHHS$  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 19#s:nt9  
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    tlens = 3.767 + 0.04*A                  'Lens thickness p"'knZG  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction ^$>Q6.x?*)  
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    'Adjust parameters to account for accommodation A-6><X's6  
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    '************************************************************************* u)X]]6
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    'Aqueous thickness (Position of Lens) S1vUP5cZ  
    '************************************************************************* .5_zh; `  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) 4`X]$.  
    GetCustomElement eID, entity PH1jN?OEwZ  
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    parID = FindFullName( "Geometry.Arizona Eye" ) ":I@>t{H*  
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    ' Delete any shift(s) in z `T#Jiq E  
    count = 0 z<
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    While GetOperationCount(eID)>count +sY8<y@%  
        GetOperation eID, count, op UM(`Oh8  
        If op.Type="ShiftZ" Then H6.  
            DeleteOperation eID,count 9M]%h  
            count=count-1 5$PDA*]9  
        End If /z)H
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        count=count+1 >LAhc7I  
    Wend [<nmJ-V  
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    'Set new shift in &_1x-@oI2:  
    op.Type = "ShiftZ" Dug{)h_2  
    op.val1 = taq #;(Q \  
    op.parent = parID 0Yo(pW,k  
    AddOperation eID, op xoB "hNIX  
    Print "Set aqueous humor thickness = " & taq-0.55 "KHe6otmi_  
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    '************************************************************************* hpBn_  
    'Radius and conic constant of anterior lens $/)0iL{0  
    '************************************************************************* uQmt
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    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" )
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    GetConic eID, entity, curv, conic Qd"R@+i  
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    SetConic eID, entity, 1/Rant, CCant K&IHt?vh!  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant V9\y*6#Y,  
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    '************************************************************************* ?l?_8y/ww  
    'Radius and conic constant of posterior lens lHc|:vG?  
    '************************************************************************* +ab#2~,)  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) 5T-CAkR{n  
    GetConic eID, entity, curv, conic 8(@Y@`/  
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    SetConic eID, entity, 1/Rpost, CCpost @wTRoMHPQ  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost Yw6d-5=:  
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    '************************************************************************* 0ZJN<AzbA  
    'Lens thickness (Position of posterior lens surface) J,_IHzO~Z  
    '************************************************************************* ~E3"
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) eFz!`a^dX  
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    ' Delete any z-shift(s)  KrqO7  
    count = 0 |QO)xEn~  
    While GetOperationCount(eID)>count feA(Rj  
        GetOperation eID, count, op Q39;bz
  
        If op.Type="ShiftZ" Then j=V2~ xA6  
            DeleteOperation eID,count a-Ne!M[  
            count=count-1 ;yDXo\gm  
        End If W:y'a3~  
        count=count+1 ]D\p<4uepM  
    Wend FZ@8&T   
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    'Set new z-shift `\Hs{t]  
    op.Type = "ShiftZ" )A*Sl2ew  
    op.val1 = tlens jx-8%dxtZ  
    op.parent = parID |7:{vA5  
    AddOperation eID, op gH[lpRu|7  
    Print "Set lens thickness = " & tlens 9 :FzSD   
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    '************************************************************************* x5YHmvy/l  
    'Lens index of refraction n,
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    '************************************************************************* JNSH'9!n6  
    eID = FindMaterial( "Lens" ) nH(Hk%~  
    GetModelMaterial eID, mat &k0c|q]  
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    mat.Nd = nlens ;h#nal>w@S  
    SetModelMaterial eID, mat SO}en[()O  
    Print "Set lens index of refraction = " & nlens bl-t>aO*.V  
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    '************************************************************************* /u N3"m5i  
    'Pupil diameter tX.{+yyU  
    '************************************************************************* VsR`y]"g  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) pTzfc`~xv  
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    'Adjust pupil diameter (trimming volume inner hole) x|IG'R1:Y  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ~zA{=|I2  
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    ' Adjust pupil location to just in front of the lens !Knv/:+  
    parID = FindFullName( "Geometry.Arizona Eye" )  zFk@Y  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) zV=(e( [  
    count = 0 !>L+q@l)  
    While GetOperationCount(eID)>count WX9pJ9d  
        GetOperation eID, count, op KqT~MP
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        If op.Type="ShiftZ" Then #$(wfb9  
            DeleteOperation eID,count #p^r)+\3=  
            count=count-1
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        End If tf@x}  
        count=count+1 NurbioFL  
    Wend M[ZuXH}  
    op.Type = "ShiftZ" -hP-w>  
    op.val1 = taq-0.01 ALY% h!L  
    op.parent = parID  /,Sd  
    AddOperation eID, op dj0`Q:VZ  
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    Print "Set pupil diameter = " & pupilDiam S.Fip_  
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    'Update AZ Eye subassembly Description b1{XGK'  
    eID = FindFullName( "Geometry.Arizona Eye" ) lt&30nf=  
    GetEntity eID, entity e`Z3
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    entity.Description = "Accommodation = " & A & "D" I#tEDeF2  
    SetEntity eID, entity 'd@Vusq}2  
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    Update <AB.`["  
    Print "DONE!" 4)3!n*I  
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End Sub NR)[,b\v  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： XU#nqvS`.  
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Accommodation = 4 Diopters dsxaxbVj%  
Pupil Diameter = 4 mm
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Set aqueous humor thickness = 2.81 x6x6N&f?  
Set anterior lens radius = 10.4 and conic constant = -2.375869 _(\\>'1q!  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 6)eU &5z1?  
Set lens thickness = 3.927 Pk; 9\0k7  
Set lens index of refraction = 1.42672 "lf_`4  
Set pupil diameter = 4 {&c%VVZb:Z  
DONE! s `r tr